1. Field of the Invention
The present invention relates generally to improvements in trailer hitches and more particularly, but not by way of limitation, to safety equipment usable with trailer hitches of the ball and socket type.
2. Brief Description of the Prior Art
A conventional type of trailer hitch that is in widespread use includes a hitch member which is mounted on a vehicle which is to tow a trailer and has a ball portion at its upper end. A socket formed in the tongue of the trailer to be towed receives the ball and a locking mechanism is provided in the trailer tongue to hold the ball in the socket once the socket has been placed over the ball. An important feature of this type of trailer hitch, from the viewpoint of the user, is the ease with which it can be used. A trailer can be connected to a towing vehicle by merely placing the socket in the trailer tongue over the ball of the hitch member, which can be permanently mounted on the towing vehicle, followed by engaging the locking mechanism in the trailer tongue.
While the ball and socket type of trailer hitching system is thus very convenient to the user, problems have arisen with the use of this type of system. A well known danger that exists with regard to these systems is that the locking mechanism in the trailer tongue can work loose while the trailer is being towed. If this occurs, the trailer can separate from the towing vehicle to become a danger to persons using the public thoroughfare along which the trailer and towing vehicle are moving. Because of this danger, a number of states require that the ball and socket hitch be supplemented by chains that connect the trailer to the vehicle so that, should the ball become dislodged from the socket, the trailer and towing vehicle will remain connected. Thus, the driver of the towing vehicle will retain at least some control over the movement of the trailer and, it is hoped, be able to bring the trailer and towing vehicle safely to a half. Unfortunately, these hopes are often not realized in practice. Because of the flexibility of the chains, the driver's control over the movements of the towing vehicle and trailer may be very limited. For example, the chains may have been connected in such a way that the front end of the trailer can undergo rapid side-to-side movements that make it very difficult for the driver of the towing vehicle to maintain control of the trailer and towing vehicle system as he brings them to a halt. Thus, while the chains may prevent the trailer from breaking loose from the towing vehicle, they may do so at the expense of causing the combined vehicle and trailer system to become a danger which is often equal or greater than the danger that would be presented by a freely moving trailer.
A second problem, often not recognized by the user of a trailer, stems from an inherent characteristic of the ball and socket connection. In order to meet various road conditions, this connection must have some freedom of movement and such freedom of movement is built into the ball and socket connection via the shaping of the ball. That is, the trailer tongue can pivot on the ball about substantially any diametric axis through the ball. Moreover, the pivotation along an axis extending longitudinally of the trailer tongue can generally be fairly large. This freedom of movement of the trailer tongue about its longitudinal axis permits the trailer to sway from side-to-side and, if the trailer has been improperly loaded so that it is top heavy, the swaying of the trailer can build up to an extent that the trailer begins to topple. Because of the large angle of pivotation that the ball and socket connection permits the trailer tongue to undergo about its longitudinal axis before encountering any resistance, the connection between the trailer and the towing vehicle may not be able to prevent such toppling from occurring. Either the trailer will be broken loose from the vehicle or, in some cases, the toppling of the trailer can cause the towing vehicle to be overturned.
While these problems can be overcome, practical considerations have, in the past, militated against their solution. As has been previously noted, a major advantage of the ball and socket trailer hitch is the ease with which such trailer hitch can be used; that is, the advantage is one of convenience. The user of a trailer expects this convenience and is generally unwilling to accept a hitching system which, though perhaps safer than the ball and socket hitching system, would be very difficult to use. In addition, the expense of a hitching system can very well deter the user from employing it to supplement the conventional ball and socket system. Moreover, another consideration that can deter a trailer user from employing a particular type of hitching system, even though it has a safety advantage over the ball and socket system, stems from the fact that the towing vehicle is often a family automobile. The ball hitch is an unobtrusive addition to the automobile so that it can be permanently mounted on the automobile without interfering with other uses; for example, transportation to social affairs, to which the automobile might be put. Thus, while solutions to the problems discussed above can be found, such solutions have generally not been employed prior to the present invention. Instead, users have generally relied on the ball and socket trailer hitch with the use of chains to supplement the connection between the vehicle and trailer that is provided by the ball and socket system.